\Bibitem{Tsa90} \by I.~G.~Tsar'kov \paper Properties of the sets that have a~continuous selection from the operator~$P^\delta$ \jour Mat. Zametki \yr 1990 \vol 48 \issue 4 \pages 122--131 \mathnet{http://mi.mathnet.ru/mzm3376} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=1093145} \zmath{https://zbmath.org/?q=an:0729.46011} \transl \jour Math. Notes \yr 1990 \vol 48 \issue 4 \pages 1052--1058 \crossref{https://doi.org/10.1007/BF01139608} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=A1990FP38300030}